The characteristics of permanent magnets have improved significantly in recent years. An example of widely used permanent magnet is a sintered magnet made by sintering a magnetic material. Sintered magnets provide superior characteristics as magnets, but there are many productivity problems associated with the manufacture of sintered magnets.
Research has been done on sintered magnets as well as magnets in which magnetic material has been solidified with resin. With these magnets, mechanical strength is obtained by binding magnetic material with thermosetting epoxy resin. However, the deterioration of magnetic characteristics in magnets that use epoxy resin is a current problem, and adequate magnetic characteristics have not been achieved.
Patent Documents 1 through 3 below describe magnets that use epoxy resin. These patent documents describe technologies for improving magnetic characteristics and the like.
Patent Document 4 provides a different binding agent from epoxy resin and describes a magnet in which rare-earth magnetic powder particles are bound with SiO2 and/or Al2O3. Also, Patent Document 5 describes an inorganic bond magnet filled with an oxide glass material in which fine oxide magnetic particles are dispersed.
(Patent Document 1) JP-A-11-238640
(Patent Document 2) JP-A-11-067514
(Patent Document 3) JP-A-10-208919
(Patent Document 4) JP-A-10-321427
(Patent Document 5) JP-A-8-115809
A problem associated with conventional magnets that use epoxy resin as a binding agent is that when compression molding of a mixture of magnetic material and epoxy resin is performed, the epoxy resin pushes away magnetic particles, making it difficult to improve the amount of magnetic particles that can be used to fill the mixture. As a result, superior characteristics are difficult to obtain with magnets that use epoxy resin as the binder.
The object of the present invention is to provide a magnet in which magnet material is bound with a binding agent in which the magnetic characteristics are improved, and a method for making the same.